Space Station "Gamma III" from the Japanese sci-fi monster flick "THE GREEN SLIME" consisted of several spheres linked together this way, although the tubes linking them together formed a circle. It amazes me how many movie space stations are round, and rotate-- without anyone realizing the point of rotation is to cause artificial gravity-- or that in order for that to work, the floor needs to be circular, with "up" being the center of rotation. (The space station in "MOONRAKER" being one of the most utterly non-sensical-- and that was in 1979!!)